Another problem, flickering lights

Ever since I got my 98 Sportage, all the lights will flicker when the car is idling. Interior, dash, head and tail lights. I had the alternator checked last year and the shop said it was fine. I got a new battery this winter and this didn't stop the flickering either.
Is this just a problem I'll be dealing with forever or is there some other problem I should be looking into.
I just love my Sportage! My teenager is even learning to drive it and she loves it even though it is a clutch. I've just had so many little nickle and dime and $100 problems I am thinking of giving it up!
Thanks for the help!

Ever since I got my 98 Sportage, all the lights will flicker when the car is idling. Interior, dash, head and tail lights. I had the alternator checked last year and the shop said it was fine. I got a new battery this winter and this didn't stop the flickering either.
Is this just a problem I'll be dealing with forever or is there some other problem I should be looking into.
I just love my Sportage! My teenager is even learning to drive it and she loves it even though it is a clutch. I've just had so many little nickle and dime and $100 problems I am thinking of giving it up!
Thanks for the help!

You have a intermittent/bad ground. Sportys are known for that problem.

Where would I start to find the ground problem? And can it be fixed. I have never lost my headlights, they just seem dim sometimes.
Thanks!

Several problems, including flickering instrument panel needles, are traced to poor ground. As a starter I would:
run engine, turn lights ON, and take a voltage measurement between battery negative and engine metal:should read zero or a few tenths of a volt max.
Take same measurement between battery negative and body ground (firewall)
should read zero or a few tenths of a volt max.
..OR/AND connect a heavy gauge wire between battery ground and engine block (running and lights ON) , ons end solidly tied, the other connectoing ON and OFF to see ig that changes the light intensity.
RUning heavy gauge wires from battery NEG to one solid engine bolt, and another between NEG and firewall is a quick shortcut to systematic research for the trouble. IN fact, since vehicle does start, the ground is definitely connected to engine: most problematic is ground continuity to body ground and ground distribution circuit, a little bit more elusive.
Report initial findings.
On a more basic tone: check alternator for proper belt tightening....